astro/basic/venus_events.go
starainrt 3ffdbe0034
feat: 扩展天文计算能力
- 新增日食、月食、本地可见性、中心线、半影区域、SVG 图示与沙罗周期信息
- 新增行星冲合、留、方照、物理星历、视直径、相位、亮肢角、轨道节点等计算
- 新增木星伽利略卫星位置、现象与接触事件计算
- 新增恒星星表、星座判定、自行修正与观测辅助能力
- 新增 coord、formula、orbit、sundial、lite/sun、lite/moon 等扩展包
- 完善农历年号、月相英文别名、视差角、大气质量、折射、日晷与双星计算
- 增加 NASA、JPL Horizons、IMCCE 等回归测试数据与基线测试
- 重构基础算法文件组织,补充大量公开 API 注释和语义回归测试
- 更新中文和英文 README,补充示例、精度说明、SVG 配图
2026-05-01 22:38:44 +08:00

365 lines
8.7 KiB
Go

package basic
import (
"math"
. "b612.me/astro/tools"
)
const (
VENUS_S_PERIOD = 1 / ((1 / 224.701) - (1 / 365.256363004))
venusEventSearchN = 16
)
func venusSunLongitudeDelta(jde float64) float64 {
sub := Limit360(VenusApparentLo(jde) - HSunApparentLo(jde))
if sub > 180 {
sub -= 360
}
if sub < -180 {
sub += 360
}
return sub
}
func venusSunLongitudeDeltaN(jde float64, n int) float64 {
sub := Limit360(VenusApparentLoN(jde, n) - HSunApparentLoN(jde, n))
if sub > 180 {
sub -= 360
}
if sub < -180 {
sub += 360
}
return sub
}
func venusSunRADelta(jde float64) float64 {
sub := Limit360(VenusApparentRa(jde) - SunApparentRa(jde))
if sub > 180 {
sub -= 360
}
if sub < -180 {
sub += 360
}
return sub
}
func venusRADerivative(jde, val float64) float64 {
sub := VenusApparentRa(jde+val) - VenusApparentRa(jde-val)
if sub > 180 {
sub -= 360
}
if sub < -180 {
sub += 360
}
return sub / (2 * val)
}
func venusRADerivativeN(jde, val float64, n int) float64 {
sub := VenusApparentRaN(jde+val, n) - VenusApparentRaN(jde-val, n)
if sub > 180 {
sub -= 360
}
if sub < -180 {
sub += 360
}
return sub / (2 * val)
}
func venusSunElongationN(jde float64, n int) float64 {
lo1, bo1 := VenusApparentLoBoN(jde, n)
lo2 := SunApparentLo(jde)
bo2 := HSunTrueBoN(jde, n)
return StarAngularSeparation(lo1, bo1, lo2, bo2)
}
func venusElongationDerivative(jde, val float64) float64 {
sub := VenusSunElongation(jde+val) - VenusSunElongation(jde-val)
if sub > 180 {
sub -= 360
}
if sub < -180 {
sub += 360
}
return sub / (2 * val)
}
func venusElongationDerivativeN(jde, val float64, n int) float64 {
sub := venusSunElongationN(jde+val, n) - venusSunElongationN(jde-val, n)
if sub > 180 {
sub -= 360
}
if sub < -180 {
sub += 360
}
return sub / (2 * val)
}
func venusConjunction(jde float64, next uint8) float64 {
//0=last 1=next
nowSub := venusSunLongitudeDeltaN(jde, venusEventSearchN)
pos := math.Abs(venusSunLongitudeDeltaN(jde+1/86400.0, venusEventSearchN)) - math.Abs(nowSub)
if pos >= 0 && next == 1 && nowSub > 0 {
jde += VENUS_S_PERIOD/8.0 + 2
}
if pos >= 0 && next == 1 && nowSub < 0 {
jde += VENUS_S_PERIOD/6.0 + 2
}
if pos <= 0 && next == 0 && nowSub < 0 {
jde -= VENUS_S_PERIOD/8.0 + 2
}
if pos <= 0 && next == 0 && nowSub > 0 {
jde -= VENUS_S_PERIOD/6.0 + 2
}
for {
nowSub := venusSunLongitudeDeltaN(jde, venusEventSearchN)
pos := math.Abs(venusSunLongitudeDeltaN(jde+1/86400.0, venusEventSearchN)) - math.Abs(nowSub)
if math.Abs(nowSub) > 24 || (pos > 0 && next == 1) || (pos < 0 && next == 0) {
if next == 1 {
jde += 8
} else {
jde -= 8
}
continue
}
break
}
JD1 := jde
for {
JD0 := JD1
stDegree := venusSunLongitudeDelta(JD0)
stDegreep := (venusSunLongitudeDelta(JD0+0.000005) - venusSunLongitudeDelta(JD0-0.000005)) / 0.00001
JD1 = JD0 - stDegree/stDegreep
if math.Abs(JD1-JD0) <= 0.00001 {
break
}
}
return TD2UT(JD1, false)
}
func LastVenusConjunction(jde float64) float64 {
return venusConjunction(jde, 0)
}
func NextVenusConjunction(jde float64) float64 {
return venusConjunction(jde, 1)
}
func NextVenusInferiorConjunction(jde float64) float64 {
date := NextVenusConjunction(jde)
if EarthVenusAway(date) > EarthAway(date) {
return NextVenusConjunction(date + 2)
}
return date
}
func NextVenusSuperiorConjunction(jde float64) float64 {
date := NextVenusConjunction(jde)
if EarthVenusAway(date) < EarthAway(date) {
return NextVenusConjunction(date + 2)
}
return date
}
func LastVenusInferiorConjunction(jde float64) float64 {
date := LastVenusConjunction(jde)
if EarthVenusAway(date) > EarthAway(date) {
return LastVenusConjunction(date - 2)
}
return date
}
func LastVenusSuperiorConjunction(jde float64) float64 {
date := LastVenusConjunction(jde)
if EarthVenusAway(date) < EarthAway(date) {
return LastVenusConjunction(date - 2)
}
return date
}
func venusRetrograde(jde float64) float64 {
//0=last 1=next
lastHe := LastVenusConjunction(jde)
nextHe := NextVenusConjunction(jde)
nowSub := venusSunRADelta(jde)
if nowSub > 0 {
jde = lastHe + ((nextHe - lastHe) / 5.0 * 3.5)
} else {
jde = lastHe + 10
}
for {
nowSub := venusRADerivativeN(jde, 1.0/86400.0, venusEventSearchN)
if math.Abs(nowSub) > 0.5 {
jde += 5
continue
}
break
}
JD1 := jde
for {
JD0 := JD1
stDegree := venusRADerivative(JD0, 0.5/86400.0)
stDegreep := (venusRADerivative(JD0+10.0/86400.0, 0.5/86400.0) - venusRADerivative(JD0-10.0/86400.0, 0.5/86400.0)) / (20.0 / 86400.0)
JD1 = JD0 - stDegree/stDegreep
if math.Abs(JD1-JD0) <= 20.0/86400.0 {
break
}
}
min := eventZeroRefine(JD1, 10.0/86400.0, 0.5/86400.0, func(jd float64) float64 {
return venusRADerivative(jd, 0.5/86400.0)
})
//fmt.Println((min - lastHe) / (nextHe - lastHe))
return TD2UT(min, false)
}
func NextVenusRetrograde(jde float64) float64 {
date := venusRetrograde(jde)
if date < jde {
nextHe := NextVenusConjunction(jde)
return venusRetrograde(nextHe + 2)
}
return date
}
func LastVenusRetrograde(jde float64) float64 {
lastHe := LastVenusConjunction(jde)
date := venusRetrograde(lastHe + 2)
if date > jde {
lastLastHe := LastVenusConjunction(lastHe - 2)
return venusRetrograde(lastLastHe + 2)
}
return date
}
func NextVenusProgradeToRetrograde(jde float64) float64 {
date := NextVenusRetrograde(jde)
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
if sub > 180 {
return NextVenusRetrograde(date + VENUS_S_PERIOD/2)
}
return date
}
func NextVenusRetrogradeToPrograde(jde float64) float64 {
date := NextVenusRetrograde(jde)
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
if sub < 180 {
return NextVenusRetrograde(date + 12)
}
return date
}
func LastVenusProgradeToRetrograde(jde float64) float64 {
date := LastVenusRetrograde(jde)
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
if sub > 180 {
return LastVenusRetrograde(date - 12)
}
return date
}
func LastVenusRetrogradeToPrograde(jde float64) float64 {
date := LastVenusRetrograde(jde)
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
if sub < 180 {
return LastVenusRetrograde(date - VENUS_S_PERIOD/2)
}
return date
}
func VenusSunElongation(jde float64) float64 {
lo1, bo1 := VenusApparentLoBo(jde)
lo2 := SunApparentLo(jde)
bo2 := HSunTrueBo(jde)
return StarAngularSeparation(lo1, bo1, lo2, bo2)
}
func venusGreatestElongation(jde float64) float64 {
lastHe := LastVenusConjunction(jde)
nextHe := NextVenusConjunction(jde)
nowSub := venusSunRADelta(jde)
if nowSub > 0 {
jde = lastHe + ((nextHe - lastHe) / 5.0 * 2.5)
} else {
jde = lastHe + ((nextHe - lastHe) / 5.0)
}
for {
nowSub := venusElongationDerivativeN(jde, 1.0/86400.0, venusEventSearchN)
if math.Abs(nowSub) > 0.15 {
jde += 5
continue
}
break
}
JD1 := jde
for {
JD0 := JD1
stDegree := venusElongationDerivative(JD0, 2.0/86400.0)
stDegreep := (venusElongationDerivative(JD0+15.0/86400.0, 2.0/86400.0) - venusElongationDerivative(JD0-15.0/86400.0, 2.0/86400.0)) / (30.0 / 86400.0)
JD1 = JD0 - stDegree/stDegreep
if math.Abs(JD1-JD0) <= 30.0/86400.0 {
break
}
}
min := eventZeroRefine(JD1, 15.0/86400.0, 0.5/86400.0, func(jd float64) float64 {
return venusElongationDerivative(jd, 0.5/86400.0)
})
//fmt.Println((min - lastHe) / (nextHe - lastHe))
return TD2UT(min, false)
}
func NextVenusGreatestElongation(jde float64) float64 {
date := venusGreatestElongation(jde)
if date < jde {
nextHe := NextVenusConjunction(jde)
return venusGreatestElongation(nextHe + 2)
}
return date
}
func LastVenusGreatestElongation(jde float64) float64 {
lastHe := LastVenusConjunction(jde)
date := venusGreatestElongation(lastHe + 2)
if date > jde {
lastLastHe := LastVenusConjunction(lastHe - 2)
return venusGreatestElongation(lastLastHe + 2)
}
return date
}
func NextVenusGreatestElongationEast(jde float64) float64 {
date := NextVenusGreatestElongation(jde)
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
if sub > 180 {
return NextVenusGreatestElongation(date + 1)
}
return date
}
func NextVenusGreatestElongationWest(jde float64) float64 {
date := NextVenusGreatestElongation(jde)
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
if sub < 180 {
return NextVenusGreatestElongation(date + 1)
}
return date
}
func LastVenusGreatestElongationEast(jde float64) float64 {
date := LastVenusGreatestElongation(jde)
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
if sub > 180 {
return LastVenusGreatestElongation(date - 1)
}
return date
}
func LastVenusGreatestElongationWest(jde float64) float64 {
date := LastVenusGreatestElongation(jde)
sub := Limit360(VenusApparentRa(date) - SunApparentRa(date))
if sub < 180 {
return LastVenusGreatestElongation(date - 1)
}
return date
}